The present invention relates to a fluid-lubricated type tapered roller bearing device having an outer ring, an inner ring and tapered rollers. In addition, the invention relates to a vehicle pinion shaft supporting assembly having a pinion shaft such as a differential, transaxle or transfer gearbox.
As a related tapered roller bearing device, there is a tapered roller bearing device in which a face rib is provided on an inner ring in such a manner as to contact large end faces of the tapered rollers. In this tapered roller bearing device, the face rib is formed on the inner ring in such a manner as to contact the large end faces of the tapered rollers, and the large end faces of the tapered rollers is supported by the face rib during the tapered roller bearing device is in operation, so that the tapered rollers are positioned at a predetermined position.
In the related tapered roller bearing device, however, since the tapered rollers and the face rib are rubbed by each other during the operation, there is caused a problem that seizing is caused on the face rib which is in contact with the large end faces of the tapered rollers and on the large end faces of the tapered rollers which are in contact with the face rib.
As a related tapered roller bearing device, there is a tapered roller bearing device which is described in JP-A-11-48805 (Patent Document No. 1). This tapered roller bearing device supports a pinion shaft of a differential. This tapered roller bearing device is designed to receive oil inside a differential case which is splashed up thereagainst by a ring gear of the differential. This tapered roller bearing device is made to receive a large amount of oil in order to eliminate a concern about a fire that may be caused on a motor vehicle having a differential due to seizing of the tapered roller bearing device.
In the tapered roller bearing device, however, while the seizing of the tapered roller bearing device can be prevented in an ensured fashion, the rotational torque of the tapered roller bearing device is increased due to the large amount of oil that is supplied to the tapered roller bearing device, and this leads to a problem that the running cost of the differential is increased to thereby deteriorate the fuel economy (efficiency) of a motor vehicle which is equipped with this differential.
Patent Document No. 1: JP-A-11-48805